Question

<body>
   <div class="navbar-collapse collapse inverse" id="navbar-header">
      <div class="container-fluid">
         <div class="about">
            <h4>text</h4>
            <p class="text</p>
            <div class="imgWrapper">
                <img id="photo" src="path/to/file"/>
            </div>
        </div>
           <div class="social">
            <p>text</p>
           </div>
       </div>
   </div>

    <div class="navbar navbar-static-top navbar-dark bg-inverse">
    <div class="container-fluid">
        <a id="logoutButton" href="logout.php" class="btn btn-lg btn-     
          primary">Logout</a>
        <button id="navbar-button" class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar-header" aria-controls="navbar-header" aria-expanded="false" aria-label="Toggle navigation"></button>
        <a href="#" class="navbar-brand">Media Manager</a>
            </div>
    </div>

    <section class="jumbotron text-xs-center">
      <div class="container">
        <h1 class="jumbotron-heading">Album list</h1>
        <p id="jumbotron-header-text" class="lead text-muted">text</p>
          <p>
              <div id="fakeButton" class="col-sm-4 col-xs-4">
                  <label for="files" class="btn btn-primary btn-lg">Select Image</label>
                  <input id="files" style="visibility:hidden;" type="file">
              </div>
          </p>
      </div>
    </section>

...

我正试图在我的Jumbotron上将id为“fakeButton”的元素居中，而我却惨遭失败。我尝试过的事情：

1）CSS选择器

#fakeButton {
    margin: auto !important;
    float: none !important;
}

2）使用bootstrap类text-center：

<div class="span7 text-center"></div>

我正在使用Bootstrap 4.大部分代码都来自此Bootstrap示例：

http://v4-alpha.getbootstrap.com/examples/album/

我确保正确安装了Bootstrap，但我似乎无法弄清楚如何将该元素集中在一起。

Answer 1

在text-center上使用带有col-xs-12的Bootstrap #fakeButton课程。

使用：

<div id="fakeButton" class="col-xs-12 text-center">
    <label for="files" class="btn btn-primary btn-lg">Select Image</label>
    <input id="files" style="visibility:hidden;" type="file">
</div>

而不是：

<div id="fakeButton" class="col-sm-4 col-xs-4">
    <label for="files" class="btn btn-primary btn-lg">Select Image</label>
    <input id="files" style="visibility:hidden;" type="file">
</div>

请看下面的代码段：

＆＃13;

<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<body>
   <div class="navbar-collapse collapse inverse" id="navbar-header">
      <div class="container-fluid">
         <div class="about">
            <h4>text</h4>
            <p class="text"></p>
            <div class="imgWrapper">
                <img id="photo" src="path/to/file"/>
            </div>
        </div>
           <div class="social">
            <p>text</p>
           </div>
       </div>
   </div>

    <div class="navbar navbar-static-top navbar-dark bg-inverse">
    <div class="container-fluid">
        <a id="logoutButton" href="logout.php" class="btn btn-lg btn-     
          primary">Logout</a>
        <button id="navbar-button" class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar-header" aria-controls="navbar-header" aria-expanded="false" aria-label="Toggle navigation"></button>
        <a href="#" class="navbar-brand">Media Manager</a>
            </div>
    </div>

    <section class="jumbotron text-xs-center">
      <div class="container">
        <h1 class="jumbotron-heading">Album list</h1>
        <p id="jumbotron-header-text" class="lead text-muted">text</p>
          <p>
              <div id="fakeButton" class="col-xs-12 text-center">
                  <label for="files" class="btn btn-primary btn-lg">Select Image</label>
                  <input id="files" style="visibility:hidden;" type="file">
              </div>
          </p>
      </div>
    </section>

＆＃13;

希望这有帮助！

Answer 2

您的标记不正确，请更改以下内容：

此：

  <p class="text</p>

对此：

  <p class="text"></p>

而且：

 <div id="fakeButton" class="col-sm-4 col-xs-4">

对此：

 <div id="fakeButton" class="col-xs-12">

text-xs-center元素中的班级.jumbotron已经将按钮居中。

该按钮具有display: inline-block，这就是为什么它以其祖先声明的text-align: center为中心。

编辑：

你真的有更多要纠正的事情：

将#fakeButton换成.row而不是<p>代码。

改变这个：

<p>
  <div id="fakeButton" class="col-xs-12">
    <label for="files" class="btn btn-primary btn-lg">Select Image</label>
    <input id="files" style="visibility:hidden;" type="file">
  </div>
</p>

对此：

<div class="row">
  <div id="fakeButton" class="col-xs-12">
    <label for="files" class="btn btn-primary btn-lg">Select Image</label>
    <input id="files" style="visibility:hidden;" type="file">
  </div>
</div>

然后将其添加到您的CSS：

input[type="file"] {
    display: block;
}

＆＃13;

input[type="file"] {
  display: block;
}

＆＃13;

<link href="https://v4-alpha.getbootstrap.com/dist/css/bootstrap.min.css" rel="stylesheet" />
<div class="navbar-collapse collapse inverse" id="navbar-header">
  <div class="container-fluid">
    <div class="about">
      <h4>text</h4>
      <p class="text"></p>
      <div class="imgWrapper">
        <img id="photo" src="path/to/file" />
      </div>
    </div>
    <div class="social">
      <p>text</p>
    </div>
  </div>
</div>

<div class="navbar navbar-static-top navbar-dark bg-inverse">
  <div class="container-fluid">
    <a id="logoutButton" href="logout.php" class="btn btn-lg btn-     
          primary">Logout</a>
    <button id="navbar-button" class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar-header" aria-controls="navbar-header" aria-expanded="false" aria-label="Toggle navigation"></button>
    <a href="#" class="navbar-brand">Media Manager</a>
  </div>
</div>

<section class="jumbotron text-xs-center">
  <div class="container">
    <h1 class="jumbotron-heading">Album list</h1>
    <p id="jumbotron-header-text" class="lead text-muted">text</p>
    <div class="row">
      <div id="fakeButton" class="col-xs-12">
        <label for="files" class="btn btn-primary btn-lg">Select Image</label>
        <input id="files" style="visibility:hidden;" type="file">
      </div>
    </div>
  </div>
</section>

＆＃13;

Answer 3

尝试将text-center类添加到按钮本身：

<label for="files" class="btn btn-primary btn-lg text-center">Select Image</label>

或者将你的html更改为：

<div id="fakeButton" class="col-xs-12 text-center">
    <label for="files" class="btn btn-primary btn-lg">Select Image</label>
    <input id="files" style="visibility:hidden;" type="file">
</div>

网站上的中心按钮

3 个答案:

编辑：